1. Field of the Invention
The present invention relates to a spindle motor and a hard disk drive including the same.
2. Description of the Related Art
A hard disk drive (HDD), an information storage device, reads data stored on a recording disk or writes data to a recording disk using a read/write head.
The hard disk drive requires a recording disk driving device capable of driving the recording disk. In the recording disk driving device, a small spindle motor is used.
An upper portion of the spindle motor has a rotor hub mounted thereon on which the recording disk is mounted, wherein the rotor hub has a disk shape extended in a radial direction, based on a shaft. Therefore, the recording disk mounted on the rotor hub may be fixed by a clamp provided on an upper surface of the rotor hub in an axial direction.
However, according to the related art, a thickness standard of a hard disk drive (HDD) is 9.5 mm in a hard disk drive for a mobile device and 15 mm in a hard disk drive for a server. Therefore, a spindle motor mounted in the hard disk drive may be somewhat elongated in the axial direction. That is, a bearing span between upper and lower radial bearings may be sufficiently secured.
However, in accordance with the recent trend for the miniaturization of electronic devices, it has been demanded that hard disk drives used in electronic devices have a miniaturized thickness standard of 5 mm or less. Therefore, the spindle motor used in the hard disk drive has been formed to have a significantly short length in the axial direction.
In accordance with the trend for thinness in spindle motors as described above, a method of keeping the clamp provided on the upper surface of the rotor hub in the axial direction from wasting space in the axial direction has been demanded.
In addition, since an amount of lubricating fluid capable of being provided in a bearing clearance is naturally decreased in a spindle motor of which a length in the axial direction is reduced, a method of preventing scattering of the lubricating fluid has been demanded.
The following Related Art Document has disclosed a clamp member 50 provided on a hub.